Closed end tuyere coil

ABSTRACT

Tuyeres and like articles employed to deliver fluids in extremely hot environments include an arrangement for their cooling comprising a conduit in the form of a coil having a plurality of turns for passing a cooling fluid through the article at high velocities. The conduit consists of an outer tubular member closed at one end to fluid flow and an inner tubular member located within the outer tubular member so as to form an annular passageway between the members. The tubular members are in fluid communication adjacent the closed end of the outer member. Cooling fluid introduced into the conduit first passes through the conduit along the annular passageway, enters the inner tubular member adjacent the closed end of the outer member, and passes through the inner tubular member to exit from the conduit.

July 4, 1972 United States Patent Shellenberger 541 CLOSED END TUYERECOIL FOREIGN PATENTS 0R APPucATloNs Inventor: Donald J. Shellenberger,Bethel Park, Pa.

7/1856 GreatBritain..................,.......

[73] Assignee:

Jones & Laughlin Steel Corporation, Pitt- Primary Examiner Roben D.Baldwin Sburgh AttameyT. A. Zalenski and G. R. Harris T C A R T S B A .H5 0 7 9 l n 07 0 N 1 0- MP FA .4 22

Tuyeres and like articles employed to deliver fluids in extremely hotenvironments include an arrangement for their [52] [1.8.Cl.............;.................266/4l,110/1825,122/6.6,

cooling comprising a conduit in the form of a coil having a plurality ofturns for passing a cooling fluid through the article at highvelocities. The conduit consists of an outer tubular member closed atone end to fluid flow and an inner tubular member located within theouter tubular member so as to form an annular passageway between themembers. The tubu- 56] Ref n Ci lar members are in fluid communicationadjacent the closed end of the outer member. Cooling fluid introducedinto the UNITED STATES PATENTS conduit first passes through the conduitalong the annular er e mn t.m W6 h t .dg m m m s S e m u u .m MD. F l Bumn .m .03 W u t m flbm D nmm 4 .m o m m m m n i tm h sm C m 4 t I amese m m Wd wmm C r. da m m S m Pdw 22 XX ll22 55mm 66// fifi m l m u. nomm m mmm m m e cero SKKH 67 8356 8999 llll 007 2 9730 25000 1 ,9 5305 430 28 7 3 23 P'ATENTEDJUL' 4 mm 3.674.248

Fig.2

INVENTOR Donald JLSheHenberger 6 BY I his ATTORNEY CLOSED END TUYERECOIL This invention relates generally to equipment for use intransferring fluids in an extremely hot environment, and, moreparticularly, to tuyeres, monkeys and like apparatus having improvedarrangements for their cooling for use with metallurgical furnaces.

Conventionally, tuyeres, monkeys and like apparatus used in extremelyhot environments are provided with some arrangement for their coolingand their service life is dependent on the effectiveness of the coolingarrangement. While many techniques for cooling such apparatus have beendeveloped, a need still exists for a cooling arrangement which willeliminate or at least substantially reduce the frequency of failures ofsuch apparatus. The benefits to be gained by doing so are significant.For example, failures of blast furnace tuyeres, in addition to the costof furnishing a replacement tuyere, result in a loss in hot metalcapacity and efficiency which in turn increases coke consumption. Also,it is important that in case the tuyere fails along its forepart, theback of the tuyere continues to be cooled and is kept intact and inplace. The hazards resulting from melting or yielding of the tuyere andthe subsequent rupturing of the hot blast system at that point are wellunderstood by those skilled in the blast-fumace art.

It is known that the heat transfer coefficient of a moving coolingfluid, such as water, increases as the velocity of the fluid increases,so long as the flow rate exceeds some minimum value. It is, of course,possible to obtain high velocities by employing high flow rates which inturn require high pressure drops; but for various reasons, it isunsatisfactory to provide a cooling arrangement for a tuyere or likeapparatus which requires the use of high flow rates and high pressuredrops.

Accordingly, an object of the invention is to provide tuyeres and likeapparatus having a cooling arrangement by means of which improvedcooling of the apparatus is obtained, thereby extending their servicelives.

Another object of the invention is to provide such apparatus wherein thecooling arrangement enables extremely high cooling fluid velocities tobe established at low flow rates and pressure drops.

Another object of the invention is to provide such apparatus wherein thecooling arrangement maintains the feed end of the apparatus cooled andintact even though the other end has failed.

These and other objects and advantages of the invention will appear fromthe following detailed description which in connection with theaccompanying drawings describes embodiments of the invention presentlypreferred by me.

In the drawings, where like elements are designated by like referencecharacters throughout the several views:

FIG. I is a longitudinal view, partly in section, of a coolingarrangement embodying the principles of the invention;

FIG. 2 is a cross-sectional view of the cooling arrangement encased in atuyere body;

FIG. 3 is a longitudinal view, partly in section, of the coolingarrangement embodied in a tuyere structure in a manner to form part ofthe hot blast conducting surface;

FIG. 4 is an enlarged cross-sectional view of a part of the coolingarrangement.

In FIG. 2, a tuyere generally indicated at comprises a body or shell 11having a generally circular cross-sectional configuration. Body 11 ismade of copper, copper alloy, aluminum alloy or other material of highthermal conductivity, and includes a back end portion, generallyindicated at 12, and having a conical outer surface 14 and a front endportion, generally indicated at 13. In use, the tuyere is mounted in ablast furnace by means of back end portion 12, the outer surface 14 ofwhich rests in a mating surface in a tuyere cooler mounted in the blastfurnace wall. Substantially the entire front end portion 13 of thetuyere extends into the interior of the blast furnace, and hot blast isdelivered into the furnace through passage 15 extending from the backend portion to the front end portion of the tuyere.

Encased in shell 11 is a cooling arrangement, generally indicated at 16as shown in FIG. 1, for circulating a cooling fluid, such as water,through the tuyere to cool it and keep it from failing from the effectof the hot environment in which it is located. The cooling arrangementcomprises a conduit in the form of a coil having a plurality of turns17l7 for both supplying a cooling fluid to the tuyere and dischargingthe fluid from the tuyere. The conduit consists of an outer tubularmember 18 closed at one end 19 to fluid flow and adapted to be connectedto a source of water at its other end 20. Positioned within outertubular member 18 is an inner tubular member 21 which is open to fluidflow at its end 22 adjacent the closed end 19 of member 18 and adaptedto be connected to a means for receiving water discharged from thetuyere at its other end 23. The outer tubular member is constructed ofcopper, copper alloys or other material of high thermal conductivity.The inner tubular member can be constructed of a material of highthermal conductivity also, although satisfactory operation of thecooling arrangement does not require it.

The outside diameter of inner tubular member 21 is smaller than theinside diameter of outer tubular member 18 whereby the tubular memberscooperate to form an annular conduit passageway 24, the inside surfaceof inner tubular member 21 forming a central conduit passageway 25. Itwill be understood that cooling water supplied to end 20 of outertubular member 18 circulates through the conduit and tuyere by firstpassing along annular conduit passage 24, then entering central conduitpassage 25 at its end 22, and passing therealong to be discharged fromthe tuyere at end 23. Spacing means 30, such as a copper rod of smalldiameter, is positioned between and along essentially the entire lengthsof tubular members 21 and 18 along the outside of turns 1717. Thisstructure insures good cooling fluid flow along the outside of theturns, which is the area in a tuyere structure requiring the greatestamount of cooling. The spacing means provides essentially only a pointcontact between the inner and outer tubular members, whereas the absenceof the spacing means might result in the inner and outer tubular memberscoming in much greater contact along the outside of turns 17-17 andessentially blocking off cooling fluid flow to that area.

In forming the spiral-shaped cooling conduit, a straight copper rod 30is spot welded to a first straight length of tubing which is toconstitute the member 21 and the tubing and rod are inserted within asecond straight length of tubing which is to constitute member 18. Theresulting; structure is coiled on a mandrel of appropriate shape andsize,making sure that the rod 30 is along the outside of the turns thatare formed. It will be understood that the passageway between thetubular members is not truly annular in shape, but may be considered assuch for purposes of this description and the accompanying claims. Afterthe cooling arrangement is formed, to manufacture the complete tuyere,the body or shell 11 is cast about the arrangement in accordance withconventional metal-casting techniques. If desired, the turns 17-17 canbe welded together to facilitate casting and to preclude hot blast fromescaping between the turns should they become exposed upon erosion ofthe shell by the hot materials: in the furnace.

Presently, I consider it advantageous to provide tubular members havingdimensions such that a ratio of cross-sectional area of the centralconduit passageway 25 to the crosssectional area of the annular conduitpassageway 24 of at least about 2 to 1 is maintained. In this manner, Iam able to maintain a cooling water velocity in the annular passagewayin excess of about 25 feet/minute at a low flow rate and with only a lowpressure drop in the central return passageway.

It will be noted that in case the front end portion 13 of the tuyeredoes fail and a breakout of the cooling arrangement 16 occurs, coolingwater can continue to be supplied to the back end portion 12 of thetuyere to cool it and maintain it intact and in place.

In the embodiment of the invention shown in FIG. 3, the turns 17-17 ofthe conduit coil abut one another and are maintained in thatrelationship by welding the turns together as shown at 26-26. A flange27 of copper, a copper alloy, aluminum alloy or some other material ofhigh thermal conductivity is cast or fabricated about a number of turns17-17 at one end of the coil. The flange has a conical surface 28 bymeans of which it is mounted in a mating surface of a tuyere cooler in afurnace wall. When so used, hot blast is conducted to the inside of thefurnace over the inside surfaces 29-29 of the turns 17-17. Because theturns l717 are held in close abutment by welds 2626, which also serve toseal off any open spaces between successive turns, the hot blast passingthrough the inside of the coil along its longitudinal axis is confinedwithin the coil and does not escape between the turns.

1 claim:

1. A tuyere, monkey or like article for use in a metallurgical furnacecomprising a coil having a plurality of successive turns maintained insubstantial abutment with one another, said coil including an outertubular member closed at one end to fluid flow and an inner tubularmember positioned within the outer tubular member, at least the outertubular member being constructed of a material of high thermalconductivity, said tubular members cooperating to form an annularconduit passageway between them, said inner tubular member forming acentral conduit passageway, the ratio of the cross-sectional area of thecentral conduit passageway to the cross-sectional area of the annularconduit passageway being at least about 2 to l and the annular conduitpassageway and the central conduit passageway being in fluidcommunication adjacent the closed end of the outer tubular member, andflange means made of a material of high thermal conductivity secured toone end of said coil for positioning and retaining the coil in saidfurnace.

2. The article of claim 1 wherein the material of high thermalconductivity is one selected from the group consisting of copper, copperalloys and aluminum alloys.

3. The article of claim 1 wherein the entire coil is encased in a shellof a material of high thermal conductivity, said outer tubular memberbeing in good heat conducting contact with the shell.

4. The article of claim 2 wherein the material of high thermalconductivity is one selected from the group consisting of copper, copperalloys and aluminum alloys.

1. A tuyere, monkey or like article for use in a metallurgical furnacecomprising a coil having a plurality of successive turns maintained insubstantial abutment with one another, said coil including an outertubular member closed at one end to fluid flow and an inner tubularmember positioned within the outer tubular member, at least the outertubular member being constructed of a material of high thermalconductivity, said tubular members cooperating to form an annularconduit passageway between them, said inner tubular member forming acentral conduit passageway, the ratio of the cross-sectional area of thecentral conduit passageway to the cross-sectional area of the annularconduit passageway being at least about 2 to 1 and the annular conduitpassageway and the central conduit passageway being in fluidcommunication adjacent the closed end of the outer tubular member, andflange means made of a material of high thermal conductivity secured toone end of said coil for positioning and retaining the coil in saidfurnace.
 2. The article of claim 1 wherein the material of high thermalconductivity is one selected from the group consisting of copper, copperalloys and aluminum alloys.
 3. The article of claim 1 wherein the entirecoil is encased in a shell of a material of high thermal conductivity,said outer tubular member being in good heat conducting contact with thesheLl.
 4. The article of claim 2 wherein the material of high thermalconductivity is one selected from the group consisting of copper, copperalloys and aluminum alloys.